eleutheria

In the world of the New Testament, freedom was first of all a legal fact. A person was either a slave or free, and the difference decided where they lived, what they owned, and whether their children were their own. This word names that condition in the abstract: not the free person but freedom itself. The related adjective ἐλεύθερος, "free," describes the person or thing that is free, and the verb ἐλευθερόω is the act of setting someone loose.

The letters take that everyday word and use it for the greatest thing that has happened to their readers. It is almost never freedom in general: it is freedom from something, given by someone, and given for something.

• Paul uses it for the standing Christ won, so that going back under the law's yoke is going back into slavery.
• James turns it into a description of the standard itself, calling God's word a law of freedom, because keeping that word is what sets a person loose.
• Paul can also use it small and practical, for one believer's right (elsewhere he calls it ἐξουσία) to eat what another would not.
• Romans looks ahead to the day creation itself is let out of decay along with God's children.
• The letters of Peter warn that the word can be a mask, promised by teachers who are themselves owned by what they cannot stop doing.

The pattern worth noticing is that this freedom is never simply being left alone. In the same breath in which Paul says his readers were called to freedom he tells them to serve one another, and Peter calls his readers free and then calls them God's servants. Being set free here means changing hands, not being handed over to yourself.